The TLS and SSL protocols use a cipher suite that determines the strength of
encryption used to protect the data. You may want to increase the strength of
encryption used when using a Oracle JVM; the IcedTea OpenJDK ships without these
restrictions in place. This step is not required to successfully use encrypted
communication.

The Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy
Files enable the use of additional cipher suites for Java in a separate JAR file
that you need to add to your Java installation. You can download this JAR file
from Oracle’s download page.
The JCE Unlimited Strength Jurisdiction Policy Files` are required for
encryption with key lengths greater than 128 bits, such as 256-bit AES encryption.

After installation, all cipher suites in the JCE are available for use but requires
configuration in order to use them. To enable the use of stronger cipher suites
with Elasticsearch security features, configure the cipher_suites parameter. See the
Configuration Parameters for TLS/SSL
section of this document for specific parameter information.

The JCE Unlimited Strength Jurisdiction Policy Files must be installed
on all nodes in the cluster to establish an improved level of encryption
strength.